The defensively-challenged Cowboys had a chance to address their secondary last year with the No. 18 overall pick in the draft. Instead, they traded the pick to the 49ers, who took LSU safety Eric Reid. …

Davis’ streak of 64 consecutive starts to open his career will be snapped Sunday when the 49ers visit the Cowboys in their season opener on Sunday. Davis, who hasn’t practiced this week, has been ruled out with a hamstring injury. …

Niners defensive tackle Ray McDonald will play in the season opener at Dallas on Sunday, a week after he was arrested on suspicion of felony domestic violence. “Yes,” Jim Harbaugh said when asked if McDonald would play against the Cowboys. “As it stands now, yes.” …

It appears one of the question marks on the 49ers’ offensive line has been answered: right tackle Anthony Davis was not on the field at the start of practice today, making it likely that Jonathan Martin will start in his place Sunday at Dallas. …

James, of course, has never had much an offensive role in his two-year, 39-carry career and his frustration hasn’t been a secret. Last year, he met with Jim Harbaugh to discuss his limited snaps and he was the subject of trade rumors in the offseason. In the spring, he skipped the first part of the 49ers offseason program, partly because of his dissatisfaction. …